Pros And Cons Of Going Over Existing Roof Material
Q. I would like to know what the pros and cons are in regards to putting on a metal roof over your existing shingles versus removing the shingles, and also if the warrenty is any different if you leave the shingles on. Thanks for your time.
A. Like all such questions, more details are required before a definitive opinion can be offered. But I can give you some guidelines here and my free booklet expands on most of these.
Regarding the seond part of your question installations of this type over approved substrates are covered by the manufacturers warranty and should in no way compromise the longevity and performance of the metal roof.Thanks for the interest, and good luck with your new roof project!
Does A Metal Roof Lower Your Insurance
That’s why having a newly installed roof can save you on insurance premiums. … Insurance companies also look favorably on metal roofing because research has shown that homes with metal roofs receive less damage from storms and house fires, which means the company is much less likely to have to pay an insurance claim.
Installing Metal Roofing Over Shingles
There are two primary methods implemented when installing metal roofing over shingles. The first is running new underlayment over an existing shingle roof, thus covering the old roof. This allows the new underlayment to act as a line of defense in the event that water somehow gets under the metal roof. The second benefit is that it acts as a buffer between the metal roof and the shingle roof. Over time, a metal roof without a buffer can cause the shingle granules to wear away against the back of the metal roofing panels.
The second method involves installing a metal roof over a shingle roof with purlins or battens. In this method, the purlins are screwed down to the roof deck, depending on how the metal roofing manufacturer has designed the panels. The metal is then installed on the purlins. This method gives the installer a nice flat surface to install the metal roofing panels down to without the many grooves and irregularities of the shingles.
Overall, it is up to you the homeowner to decide which installation method is right for you!
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Can Moisture Get Trapped Between The Metal And Asphalt Shingles
One of the benefits of a metal roof is that it is resistant to rotting and mildew. However, this benefit is cancelled out if moisture is able to get in between the new metal roofing panels and the old asphalt shingle roof.
Moisture between these surfaces can result in mold and rotting which will ultimately lead to costly repairs.
Here are two ways to eliminate trapped water vapor:
Every roof is different and must be analyzed by the roofing contractor to determine whats best for your specific roof. However, all metal roofs should have roofing underlayment regardless of whether its a new installation or being installed on top of an existing shingle roof. Roofing underlayment creates an added layer of protection from moisture.
To learn more about how ridge vents will increase airflow and lower energy costs, we suggest reading:
Installation With Fanfold Insulation
The second method of installing metal roofs over shingles is using an insulating layer. The main task of this layer is to protect the asphalt roof, which will be located under the metal, from overheating.
Since the asphalt roof will be under the metal roof, it wont be able to cool down as quickly when the sun goes down. This can lead to overheating of the home, which can cause many inconveniences. In addition, high temperatures can cause the asphalt roof composition to melt and deform.
To avoid these problems, quarter-inch insulation is used. In addition, this layer also helps in the process of installing a metal roof. It prevents the appearance of dents in the attachment points of the new metal roof.
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How To Install Metal Roofing Over Shingles Right
For many years, shingle roofs have been the best option for residential homes. Nevertheless, in our time, metal roofs are gaining more and more popularity. This is due to their reliability, quality, and durability.
When you decide to install a new metal roof, you can do it in two ways. The first way is to dismantle the old roof, and the second is to install a metal roof over shingles.
The installation of a metal roof over shingles can be done in three ways. The installation can be influenced by many factors, the condition of the existing roof, the weather conditions in the region, and additional elements. Before installation, it is necessary to inspect the roof deck to determine if it is possible to install a metal roof over shingles.
Can you put a metal roof over shingles or not will become clear after inspecting the existing roof. Based on the information received, a professional metal roof installation team will give you a detailed answer on how to install metal roof over shingles in your particular case.
Impermeable To Fire Rot And Insect Damage:
One of the prime reasons why the metal roof has gained incredible recognition by so many people is that it is virtually fireproof. Apart from this, it has other pros as well:
- Termites can never eat metal roofing.
- It is impermeable to rot, mold and mildew.
- Since the metal roofs conduct heat quickly, the snow easily slips from these roofs.
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Future Leaks Are Harder To Track And Repair
It takes skill to find a roof leak, track it, and repair it. But its even harder to do this when you install a metal roof over shingles.
If water gets under your metal panels, itll go down your old asphalt roof, find the path of least resistance, and start leaking inside your home. What makes this difficult to repair is that the leak could come from two different parts of two different roofs.
This makes it incredibly hard to find the origin of the leak in your old roof or new metal roof. If its found that its your old shingle roof, the roofing contractor has to go through the metal roof to repair it.
Thats why its important to ask your contractor about the condition of your current shingle roof if youre strongly considering installing a metal roof over it. If you already have roof leaks, its best to avoid doing it altogether.
Step : Start Putting The Metal Panels Into Place
You want to make sure to start straight and keep the edges straight. Keep everything as square and symmetrical as possible.
This also applies to running the screws in a straight line. You can place the screws on either the flat surface or the raised ridges on the roof.
These screws are used for fastening the metal. Thus, the straighter they are, the easier it will be to fasten the metal.
When you install the panels, you will have to cut the valleys by hand. You can pre-measure closely and install them as you go along, or you can cut the panels close, leaving out some of the screws, and then come back later.
Also, be careful not to scratch the colored surfaces of the metal. If you scratch the metal now, it might lead to rust or other problems later. You want to keep any gritty substances from coming into contact with the metal.
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Ridge Vents Are More Obvious
On most homes today, attic venting is provided by a continuous ridge vent that runs across the peak of the roof. On a shingled roof, this continuous ridge vent is a strip of shingle-like material that runs the entire length of the peak of the house, masking outflow holes on the sides of the ridge. You likely have seen this countless times, but probably never really noticed because the CRV usually lies very flat and blends in perfectly with the surrounding roof.
On many metal roofs, especially standing-seam roofs, the CRV is also metal, and it stands out further and is thus much more noticeable. These thick, prominent lines or ridges are inherent in metal roofs and add to their distinctive look.
You Wont Get To Replace Crucial Roofing Materials
When you get a metal roof-over, you bypass the tear-off process of getting a new roof. This will save you money, but you miss out on replacing crucial materials that are included in a full roof replacement.
For example, one of these crucial materials is the underlayment. Its your roof systems last line of defense for keeping your decking dry. When you roof over your asphalt roof with a metal roof, you have to rely on the underlayment from your old roof. You also wont get the proper kind of underlayment specifically designed for a metal roof.
Roofing materials arent meant to last forever. Thats why if youre already going to invest in a metal roof, I recommend starting from scratch with clean decking.
To learn more about the crucial materials that are replaced when you get a new roof, read this article on the 9 materials included in your roof replacement.
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Can You Put A Metal Roof On In The Winter
Aside from shoveling snow and staging the installation, metal roofing can be installed in winter. … They are also not phased by the harsh temperatures, ice, and snow. In fact, metal roofing is designed to shed water and ice, minimizing ice and snow accumulation. Additionally, metal roofing does not have to cure and seal.
Metal Panel Attachment Directly Into Shingles
One of the most cost-effective installation methods involves attaching metal panels directly through the shingles and into the wood deck below. While this method saves the cost and labor of furring strips, its important to remember that steel often acts as a mirror and can telegraph deck and shingle inconsistencies through the metal panels.
While this condition is purely aesthetic and doesnt affect panel performance, homeowners with a high emphasis on aesthetics may be better suited with a remove and replace approach or a system like our 138T, which we will address a bit later.
There are a couple of additional considerations with the direct attachment approach. First, its challenging to achieve Above Sheathing Ventilation with this installation method. ASV is critical to reducing energy consumption.
You can learn more about ASV here.
Consequently, while this approach often represents the most economical installation, it also offers reduced energy savings.
Second, its important to note that a barrier between the original shingles and the new metal roof is required for direct attachment projects. This layer of protection is critical to prevent the shingles from wearing through the metal panels as they expand and contract over the roofs life. Common barrier products include #30 felt, synthetic underlayment, or even thin foil-faced insulation.
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Ensure Your Shingle Roof Is In Good Shape
Almost every building department will comply with this installation process but may have a few caveats in terms of safety. Generally, they will check to ensure that the plywood of the existing shingle roof is in good shape and does not contain any soft spots.
This isnt just to make your life harder. A metal roof is installed with screws that need something to hold onto. Soft or unreliable plywood wont be able to hold the screws and thus your roof could come off during one of Northern Floridas famous afternoon thunderstorms. Lets not even get started on hurricane season.
Disadvantages Of Not Completely Removing Existing Shingles
As mentioned above, there are tradeoffs involved in any decision. There are a few downsides involved with leaving the old shingles in place. They include:
- Difficulty checking the framework and deck
- Having to replace your new metal roof due to undetected deck damage
- Condensation/Moisture problems
- Damaged shingles may affect new roof
- Restricted by some local building codes
- May limit or void manufacturers’ warranty
Putting aside the costs, one of the benefits of removing the old roof is that it allows contractors to evaluate the condition of the roof framework. There are ways to check without removing the roof, but they are not always as reliable as looking at it directly.
When installing a metal roof over shingles there is little chance to do any direct evaluation. Skillful roofing contractors are more practiced at evaluating your Tampa roof no matter the condition.
Be sure that your contractor carefully inspects and addresses any existing damage to your roof or shingles before adding a new metal roof. Ask how their installation will address and prevent issues with condensation. Be sure you understand how this type of installation affects the warranty on your new metal roof, as some manufacturers may limit or void warranty coverage in these situations.
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When You Shouldnt Put A Metal Roof Over Shingles
Sure, everyone would prefer to save money by bypassing the time-consuming and expensive removal of an existing roof before installing a metal one, but there are times when you just plain should not do it.
If the majority of your shingles are damaged and deteriorating, if there are saggy areas of your roof, rotting wood, or leaking issues, its better to have all new material put in underneath to ensure a safe, sound roof overhead.
After all, the whole point of choosing a metal roof is the peace of mind that comes with its durability. It doesnt make sense to place it on top of a shaky, unstable foundation.
Contact Legacy Service To Schedule An Appointment
At Legacy Service, we love just about everything about this type of roofing. When they are installed correctly using the right materials, they can withstand just about anything. And since it reflects heat from the sun, it can help you save significantly on energy costs. Its also 100% recyclable, making it eco-friendly. We have decades of experience when it comes to installing this type of roofing, and we can actually custom-make every panel for your project. We also offer a lifetime warranty, which makes for a sound investment. If youd like to learn more about metal roof replacement, contact our Legacy Service team today to schedule an appointment.
Posted on Oct 19, 2019 in Roof
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HOW LONG SHOULD A ROOF LAST?ELEMENTS
A lot of elements play a role in maintaining the integrity of the roof, but as a homeowner, the most important components to pay attention to are the underlayment, ventilation, and material.
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Choose A Quality Roofing Company
Among other things, many might think a cheaper roofing quote will help save on costs.
This may be a good idea in some cases. After all,high labor costs, expensive roofing material/s, and a hefty overall cost are a few of the many worries most homeowners face.
But remember: the purpose of performing a re-roof or installing a new roof is a long-term investment meant to protect you and your family from strong winds, hail, rain, and the occasional afternoon thunderstorms.
Interested In Putting A Metal Roof Over Shingles
All in all, it is absolutely possible to put a new metal roof over an old shingled one under the right circumstances and conditions. Not sure if your current roof is up for it? Give Werner Roofing a call!
If youre considering a metal roof, wed be happy to assess your current shingle roof to determine if its a good candidate for laying a metal roof overtop. You can count on us to give it to you straight and only make recommendations that are true to your roofs condition. We always try to save you money on your roofing project wherever possible like our free inspection, for instance! Contact our team to schedule yours today.
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How To Deal With Condensation
Your new metal roof will gather condensation if there are air pockets directly under the metal.
Condensation on your metal roof can be dealt with using a moisture barrier. This can take the form of new underlayment in many cases. Anything that prevents condensation from collecting on the metal roof.
Luckily, if this occurs it wont leak into your house as you still have the shingle roof underneath. It should still be dealt with since it can reduce the life span of your metal roof.
The Metal Roof Design
Although just any metal roof can fit over shingles, some metal roof designs or panels perform better without the shingles. You need to consider how much space you need between the metal panels and the asphalt shingles and whether the shingles will fit. Overall, the design needs to be compatible with the existing roofing.
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Question 5 Of : Can I Install Metal Roofing Over Shingles On My Own
